So I called them up today to have a chat with them.
I was told even if using torque wrench you still may snap the 10mm plug due to anti-sieze causing reduced friction over the threads causing erroneous reading by torque wrench!

They said only angle torque meters will still be OK! Also they said since they are plated they shouldn't rust and it is not recommended to use anti-sieze over these plugs!

I guess I have to make a comment on my video.

They mentioned the 10mm (FX HO MR-1 plugs) would snap at around 18 ft-lb which would be about 24 N.M!!

Reza......that is very interesting. Do you know when that bulletin was realeased? As you know I have always used antisieze & torque wrench on mine......the plugs come out very easily.
This info condradicts what Yamaha have always recommended. Reading all the forums.....I would say that most plugs have snapped due to lack of antisieze.....I think I can remember only one case of a plug snapping where antisieze was used. Next time I change the plugs I'll experiment with both angle & torque wrench / antisieze & no antisieze & cross reference each.......Interesting!

They didn't post the date of the bulletin release I just updated the video!
I would not use anti-sieze on these after my conversation with them directly!
Do not experiment this with your engine man, what if now that you know it snaps!? Not worth it!
If you decide to do this, please use minimum anti-sieze so you don't reduce the friction by much! In my video, I use anti-sieze to cover the threads fully! Not good!!!

Reason we have not snapped it in my opinion is the fact we are using a 13n.m torque requirement which is still ways away from 24 that it snaps!

I am now nervous because the tech said, many times they snap while you are taking them out!!! I am not changing these plugs until I really need to, in case I am going to snap them lol

This is not new, any type of lubricant on a bolt will alter the torque characteristic. If you use anti-seize in a bolt hole you have to reduce the torque. I am not recommending this to anyone, however, I have a car with aluminum heads and I have changed plugs dozens (ten plus each time) of times if not more. I reduced the torque to 15 ft-lbs and they have been fine.

Here is the problem, when you torque a bolt a large amount of the torque is actually used in overcoming the thread friction. Depending upon the type of lubricant in some cases you can get the same holding force with far less torque. The problem is arriving at the correct torque when you use a lubricant. I installed a set of head studs on a car recently, the torque is achieved with a nut (less friction), versus a bolt. The specs were to use about 60% of the torque required with bolt. In a affect, you have the same holding force with about 1/2 the torque, that means the a bolt used about 50% of the total torque to overcome friction. In my example the torque with a stud/nut was so low due to using a nut (versus a bolt) and a special lubricant. Keep in mind the holding forces were were the same as using a bolt and twice the torque.

If you want an in-depth explanation, the ARP (fasteners) website has a great explanation in the area that covers head studs.

Captain, I'm sure you asked and I don't know: What would happen if you put em in too loose? Jack says 15 pounds and I'd personally go with that but what if you put em in only ten and the crush washer didn't crush well - would the plugs back out or make poor contact? Would the spark be too shallow in the chamber?

Mark, I guess the guy's name was Andrew, he mentioned they snap at 18 ft-lb, I converted that and it was 24 n.m. Yamaha says torque it to 12.5/13 n.m which is equal to 9.5 ft-lb! I would not torque this to 15 ft-lb!!! That's way too tight and yet very close to 18 ft-lb!

I am talking waverunner engine ofcourse! I think the reason anti-sieze has not effected our application and snapping the plug is the fact the recommended torque by Yamaha is way lower than the torque required to snap one of these! So even with anti-sieze, lower friction, doesn't cause erroneous results as much as close to 100% (from 9.5 to 18 ft-lb). I personally will keep using anti-sieze on mine but will apply very little unlike before!

After all, as Jack said this is not anything new! My response is I agree and yet Yamaha recommended it in their service manual! Perhaps they knew their torque requirement was way low and anti-sieze won't throw it off enough to cause snapping!

To answer your question if your plug is loose, there is a chance for intermittent effective spark in case it backs out!

Originally Posted by Mark

Captain, I'm sure you asked and I don't know: What would happen if you put em in too loose? Jack says 15 pounds and I'd personally go with that but what if you put em in only ten and the crush washer didn't crush well - would the plugs back out or make poor contact? Would the spark be too shallow in the chamber?

Thank you, Sir. I don't have much experience with these. Might be buying HO soon and am trying to learn. In my lawn mowers and such I often go finger tight, no problema.
Now's as good of time as any... I enjoy and appreciate your vids. You are a good example in attitude, dare I say "role model". Thanks!

I was in the school of "almost any thread gets something - either nevr sez or locktite"! I'll go with eight or ten, then. Obviously the rating will have to be reduced when lubing - the trick is to know how much!